The high carrier mobility measured in rubrene single crystals makes its growth in the form of crystalline thin films a challenge of great interest in view of their use as semiconductor layers in integrated organic devices. Here, heteroepitaxial thin films of rubrene are grown by molecular beam epitaxy under different conditions, showing that the film structure can be tuned from disordered to crystalline by the sole control of the deposition rate. Highly oriented crystalline films are demonstrated to grow undergoing a transition characterized by a strong mass transport among different domains, persisting even during the postgrowth stages. This mechanism is rationalized within a thermodynamic model which gives quantitative predictions starting from empirical force field calculations and atomic force microscopy topographical data. By an appropriate setting of the growth parameters, an epitaxial rubrene monolayer is obtained at room temperature. These results, rationalizing the concrete possibility of growing crystalline and oriented rubrene thin films, open new perspectives to organic-based thin film technology and devices.
Campione, M., Moret, M., Raimondo, L., Sassella, A. (2009). Kinetic phase selection of rubrene heteroepitaxial domains. JOURNAL OF PHYSICAL CHEMISTRY. C, 113, 20927-20933 [10.1021/jp905752r].
Kinetic phase selection of rubrene heteroepitaxial domains
CAMPIONE, MARCELLO;MORET, MASSIMO;RAIMONDO, LUISA;SASSELLA, ADELE
2009
Abstract
The high carrier mobility measured in rubrene single crystals makes its growth in the form of crystalline thin films a challenge of great interest in view of their use as semiconductor layers in integrated organic devices. Here, heteroepitaxial thin films of rubrene are grown by molecular beam epitaxy under different conditions, showing that the film structure can be tuned from disordered to crystalline by the sole control of the deposition rate. Highly oriented crystalline films are demonstrated to grow undergoing a transition characterized by a strong mass transport among different domains, persisting even during the postgrowth stages. This mechanism is rationalized within a thermodynamic model which gives quantitative predictions starting from empirical force field calculations and atomic force microscopy topographical data. By an appropriate setting of the growth parameters, an epitaxial rubrene monolayer is obtained at room temperature. These results, rationalizing the concrete possibility of growing crystalline and oriented rubrene thin films, open new perspectives to organic-based thin film technology and devices.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.